Denosumab for Prevention of Post-Teriparatide Bone Loss in Premenopausal Women With IOP

Denosumab for Prevention of Post-Teriparatide Bone Loss in Premenopausal Women With Idiopathic Osteoporosis (IOP)

The purpose of this research study is to evaluate antiresorptive therapy with denosumab (Prolia) for prevention of bone loss after stopping teriparatide (TPTD) in premenopausal women with idiopathic osteoporosis.

Premenopausal women who have received TPTD in the FDA Orphan Diseases Program-funded trial, "A Phase 2 Study of Teriparatide for the Treatment of Idiopathic Osteoporosis in Premenopausal Women" (NCT01440803) may be eligible to participate in the current study, a 36-month open-label pilot study of denosumab (Prolia®, 60mg subcutaneous (SC) every 6 months).

The goals of the study are to estimate the effects of denosumab on central and peripheral, as well as trabecular and cortical, bone mass and microstructure and to obtain preliminary data to inform the design of a future randomized study. This study presents the first opportunity to study the effects of denosumab after TPTD in this unique and severely affected group of young women.

Funding Source: FDA Office of Orphan Products Development (OOPD).

Osteoporosis in premenopausal women with normal menstrual function and no specific cause is termed idiopathic osteoporosis (IOP). IOP is a rare disease with an estimated prevalence of <200,000 affected premenopausal women in the United States.

Denosumab, a potent inhibitor of osteoclast-mediated bone resorption, leads to continuous gains in both trabecular and cortical bone mineral density (BMD). Moreover, denosumab is not retained in the skeleton, and may thus be preferable for use in young women who may be contemplating future pregnancies. The investigators hypothesize that denosumab, initiated after completion of two years of TPTD, will maintain or improve central and peripheral areal and volumetric BMD, microstructure and stiffness in premenopausal women with IOP.

Inclusion Criteria:

• All women completing NCT01440803 who remain without a disease or medication that causes osteoporosis will be offered enrollment into this study.
• (Premenopausal status is no longer be required for entry.)

Exclusion Criteria:

• Renal insufficiency or liver disease: Creatinine, transaminase (AST)/alanine transaminase (ALT) above upper limit of normal
• Vitamin D deficiency: 25-hydroxyvitamin D (25-OHD) <30 ng/mL
• Pregnancy: urine pregnancy test must be negative